A. Field of the Invention
The present invention relates to mirrors of the type generally used by people for personal hygiene purposes such as shaving, application of cosmetics and the like. More particularly, the invention relates to a mirror having a magnification that may be readily varied by the user.
B. Description of Background Art
There are a variety of circumstances in which it would be desirable to have available a face mirror that has a variable magnification. For example, when a person who may be somewhat near-sighted wishes to install or remove contact lenses ordinary flat bathroom mirrors or portable mirrors having a one-to-one, or unity, magnification factor, are often inadequate to facilitate this task. In such cases, it would be desirable to have a magnifying mirror available for use in place of or in addition to a flat mirror with unity magnification. However, since the field of view of a magnifying mirror of a given size is inherently smaller than that of a flat, unity magnification mirror the applications for a mirror having a fixed magnification are somewhat limited. Thus, a person installing or removing contact lenses may desire to use a mirror having a reasonably large magnification, but may at other times wish to have a full face view provided by a mirror having a smaller magnification, or a conventional flat mirror having no magnification. Also, applying cosmetics, shaving, and performing other such tasks related to personal hygiene or beauty would oftentimes be facilitated by the availability of a mirror having a selectable or variable magnification.
One approach to satisfying the need for a personal hygiene mirror having different magnifications consists of a two-sided mirror, which has on one side a flat, unity magnification factor mirror, and on the other side a concave mirror having a magnification factor greater than unity, the two mirrors being assembled in a back-to-back configuration. However, the weight increase resulting from double mirrors, and the lack of variability of the magnification factor of the magnifying mirror to a precise desired value, limits the usefulness of dual magnification mirrors. Accordingly, it would be desirable to provide a variable magnification mirror suitable for personal hygiene and cosmetic applications.
A variety of prior art variable magnification mirrors have been disclosed. Prior art references disclosing such mirrors include the following U.S. Pat. Nos. 3,514,776, Mulready; 3,610,738, Bochman; 4,298,247, Michelet et al.; 4,420,222, Bret et al.; 4,422,733, Williams, Jr. et al.; 4,875,764. Marino et al.; 5,016,998, Bulley et al.; 5,074,654, Alden et al.; 5,089,915, Gobeli. Foreign references disclosing variable magnification mirrors include: Japanese Patent No. 64-42603; United Kingdom Patent No. 400,445; and Italian Patent No. 0,283,136.
Although the devices disclosed in the aforementioned prior art references may be more or less useful for their intended purposes, the devices disclosed, whether considered either separately or collectively, have characteristics which limit their usefulness for personal hygiene applications. For example, the Mulready mirror device requires the use of a mirror plate having a precisely contoured rear surface, and a vacuum chamber and control system, on the one hand, or a complex arrangement of multiple bosses and screws to bend the mirror and thereby vary its magnification.
The adjustable magnifying mirror disclosed in Bochman also utilizes a vacuum chamber to bend a mirror plate, with the inherent problems of precision adjustability and sealing against vacuum leaks.
The adjustable reflector disclosed in Williams, Jr. et al. Also requires the use of a vacuum system and associated controls.
The adjustable mirror disclosed in Wurzburger requires the use of a pre-curved mirror plate, in conjunction with various pusher plates.
In view of perceived limitations of prior art variable mirrors, the present invention was conceived of.